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The use of aperture shape controller and convergence mode in radiotherapy treatment planning

Published online by Cambridge University Press:  11 December 2020

Maija Rossi Open the ORCID record for Maija Rossi [Opens in a new window]  and
Eeva Boman Open the ORCID record for Eeva Boman [Opens in a new window]
Maija Rossi*
Affiliation:
Department of Medical Physics, Tampere University Hospital, Teiskontie 35, PO BOX 2000, 33521Tampere, Finland Department of Oncology, Tampere University Hospital, Teiskontie 35, PO BOX 2000, 33521Tampere, Finland
Eeva Boman
Affiliation:
Department of Medical Physics, Tampere University Hospital, Teiskontie 35, PO BOX 2000, 33521Tampere, Finland Department of Oncology, Tampere University Hospital, Teiskontie 35, PO BOX 2000, 33521Tampere, Finland
*
Author for correspondence: Maija Rossi, Tampere University Hospital, Teiskontie 35, PO BOX 2000, 33521Tampere, Finland. E-mail: maija.rossi@pshp.fi
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Abstract

Aim:

Studying the use of Aperture Shape Controller (ASC) and Convergence Mode (CM) in Eclipse (Varian Medical System) in terms of plan quality and complexity of volumetric modulated arc therapy (VMAT).

Materials and methods:

Forty VMAT plans were re-optimised for the prostate, prostate + lymph nodes, breast and head & neck patients retrospectively, changing the ASC settings (off, moderate, very high) and CM settings (off, on and extended).

Results:

Using ‘on’ or ‘extended’ CM increased plan quality in terms of planning target volume homogeneity and low-dose spread to the organs at risk (OAR). ‘Extended’ CM increased the optimisation time 4·3-fold compared to ‘on’, and deteriorated the plan quality in several simple planning cases. ‘Moderate’ ASC decreased plan complexity with minor effect on plan quality compared to ‘off’, but ‘very high’ ASC had larger adverse dosimetric effects. However, the ASC decreased the plan complexity only if the CM was turned ‘on’.

Findings:

Using ‘on’ CM increases the plan quality but using ‘extended’ CM is not recommended. The ‘moderate’ ASC decreased complexity without significant adverse effects on plan quality, and even ‘very high’ ASC may be used when plan simplicity is prioritised. However, if CM is not used, the ASC should also be turned off.

Keywords

aperture shape controllerconvergence modeplan complexityplan quality
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 21 , Issue 2 , June 2022 , pp. 171 - 178
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Copyright
© The Author(s), 2020. Published by Cambridge University Press

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Footnotes

This research received no specific grant from any funding agency, commercial or not-for-profit sectors.

References

van der Merwe, D, Van Dyk, J, Healy, B et al. Accuracy requirements and uncertainties in radiotherapy: a report of the international atomic energy agency. Acta Oncol 2017; 56 (1): 1–6.10.1080/0284186X.2016.1246801CrossRefGoogle ScholarPubMed
Masi, L, Doro, R, Favuzza, V, Cipressi, S, Livi, L. Impact of plan parameters on the dosimetric accuracy of volumetric modulated arc therapy. Med Phys 2013; 40 (7): 071718.10.1118/1.4810969CrossRefGoogle ScholarPubMed
Eclipse Photon and Electron Algorithms Reference Guide, Eclipse version 15.5. Varian medical Systems, Palo Alto, CA, US.Google Scholar
Binny, D, Spalding, M, Crowe, SB et al. Investigating the use of aperture shape controller in VMAT treatment deliveries. Med Dosim 2020; 45 (3): 284–292.10.1016/j.meddos.2020.02.003CrossRefGoogle ScholarPubMed
Kamima, T, Murakami, Y, Arima, M, Sato, Y, Yoshioka, M, Sato, T. Impact of aperture shape controller on volumetric modulated arc therapy treatment planning for nasopharyngeal cancer. Nihon Hoshasen Gijutsu Gakkai Zasshi 2020; 76 (4): 356–365.10.6009/jjrt.2020_JSRT_76.4.356CrossRefGoogle ScholarPubMed
Rossi, M, Boman, E, Kapanen, M. Contralateral tissue sparing in lymph node-positive breast cancer radiotherapy with VMAT technique. Med Dosim 2019; 44 (2): 117–121.10.1016/j.meddos.2018.03.005CrossRefGoogle ScholarPubMed
ICRU Report 83. Prescribing, recording, and reporting photon-beam intensity-modulated radiation therapy (IMRT). J ICRU 2010; 10 (1): 35.Google Scholar
van’t Riet, A, Mak, AC, Moerland, MA, Elders, LH, van der Zee, W. A conformation number to quantify the degree of conformality in brachytherapy and external beam irradiation: application to the prostate. Int J Radiat Oncol Biol Phys 1997; 37 (3): 731–736.10.1016/S0360-3016(96)00601-3CrossRefGoogle ScholarPubMed
Hernandez, V, Saez, J, Pasler, M, Jurado-Bruggeman, D, Jornete, N. Comparison of complexity metrics for multi-institutional evaluations of treatment plans in radiotherapy. phiRO 2018; 5: 37–43.Google ScholarPubMed
McNiven, AL, Sharpe, MB, Purdie, TG. A new metric for assessing IMRT modulation complexity and plan deliverability. Med Phys 2010; 37 (2): 505–515.10.1118/1.3276775CrossRefGoogle ScholarPubMed
Park, JM, Park, S, Kim, H, Kim, JH, Carlson, J, Ye, SJ. Modulation indices for volumetric modulated arc therapy. Phys Med Biol 2014; 59 (23): 7315–7340.10.1088/0031-9155/59/23/7315CrossRefGoogle ScholarPubMed
Du, W, Cho, SH, Zhang, X, Hoffman, KE, Kudchadker, RJ. Quantification of beam complexity in intensity-modulated radiation therapy treatment plans. Med Phys 41; 2014: 21716.10.1118/1.4861821CrossRefGoogle ScholarPubMed
Younge, KC, Matuszak, MM, Moran, JM, McShan, DL, Fraass, BA, Roberts, DA. Penalization of aperture complexity in inversely planned volumetric modulated arc therapy. Med Phys 2012; 39 (11): 7160–7170.10.1118/1.4762566CrossRefGoogle ScholarPubMed
Chiavassa, S, Bessieres, I, Edouard, M, Mathot, M, Moignier, A. Complexity metrics for IMRT and VMAT plans: a review of current literature and applications. Br J Radiol 2019; 92 (1102): 20190270.10.1259/bjr.20190270CrossRefGoogle ScholarPubMed